U.S. Pat. No. 4,898,574 (Fischell) relates to an atherectomy (tunneling catheter) device used to remove plaque and enlarge a channel through an occlusion previously crossed by a guide-wire to thereby increase blood flow. The Fischell device primarily functions as a coring device that removes tissue and includes a sharp cutting edge to cut a cylindrical bore of tissue from the occlusion and uses suction to hold it within the device. Fischell's tunneling catheter is typically comprised of a stainless steel cylinder, wherein the stainless steel cylinder tapers distally to define the cutting edge. As described, Fischell's device has an inner lumen much greater than the associated guide-wire to allow for sufficient suction and to provide space for storage of occlusive material. All of the disclosed embodiments of Fischell are for over-the-wire type devices.